Hand dryer splash guard

ABSTRACT

The invention discloses a splash guard that may be retrofitted to a hand dryer device to avoid spraying of water on the floor and on the walls. The splash guard is attached underneath the dryer device and is configured to catch the water displaced from a user&#39;s drying wet hands. The splash guard is formed of a housing that has side walls, a base, a perforated drip tray and a drawer arrangement to hold the displaced water. The housing is hollow and open fronted, for users to place their hands under the dryer device. The surface of the drip tray is anti-reflective and has perforations that stop water from splashing. The displaced water is directed to drip into the drawer that store up the exiting water to be removed at a later time. The drawer has transparent windows to indicate the level of water in the drawer.

CROSS-REFERENCES TO RELATED APPLICATION

This application is a complete specification of provisional patentapplication No. 63/148,786 entitled “HAND DRYER SPLASH GUARD” filed onDec. 2, 2021.

FIELD OF THE INVENTION

The disclosure generally relates to drying implements and in particularto a splash guard that may be attached to a hand dryer to control thespray created by the hand dryer. The product applies to Category 21(WIPO) anti spray, washrooms and drying apparatus. It also is applicableto these sub-categories D 0350 drying apparatus (serial number) S 0164110097 (Basic No) D 0351, drying apparatus and installations S 0157110222D 0348, dryers (Air) S 0161 110013, H 0023 Hair driers [dryers] S0158 110095 H 0055, Hand drying apparatus for washrooms S 0160 110223.

DESCRIPTION OF THE RELATED ART

Most washrooms are fitted with hand dryers as a cost-effective andnon-touch means of drying a person's hands. This removes the need forenvironmentally harmful hand drying methods such as paper towels, orunhygienic options such as shared towels. Traditional hand dryers relyon blowing hot air to evaporate water off of a person's hands. Newer andmore effective hand dryers tend to push water off of the hands usingconcentrated air pressure. The air pressure method forces liquid off ofthe hands of the user. The problem with the air pressure method is thatthe water being pushed by the concentrated air pressure sprays aroundthe washroom. This leaves puddles of water on the floor creating sliphazards, and germs contained in the spray are spread around thewashroom. Also mold appears on the grout between the tiles. Furthercleaning the floors and the doors at regular intervals have to be doneto get rid of the splashed water which will increase the cost of laborand cleaning products. The most sought-after hand dryers are those thatcan dry hands in the fastest way. To achieve this, they must deliverhigher air pressures, which leads to a greater spray effect.

A splash guard for hand dryers that eliminates or reduces water frombeing splashed from the hands during the drying process onto the nearbywalls and floor is disclosed in the patent application WO2013/082572.The splash guard may be configured to mount below existing wall mountedhand dryers or may include an integrated blower assembly having a blowerpositioned in the lower portion of the splash guard, such a below theoutlet nozzle and the hands being dried. The invention in CN109222717provides a hand washer capable of detecting bacteria, and belongs to thefield of cleaning devices. The hand washer includes a main housing, ahand-washing function assembly and a control panel. The hand washingfunctional assembly is installed inside the main housing, comprises amounting plate and a water supply part, a hand washing liquid part, adrying part, a bacterial detection and identification device and asensor mounted on the mounting plate, and a control board for systemcontrol is also mounted in the main case, wherein the control board isrespectively connected with the water supply part, the hand washingliquid part, the drying part, the bacterial detection and identificationdevice and the sensor.

The application WO2018/220689 discloses a hand-drying device thatcomprises a water-receiving part that includes a bottom-surface-sidewater-receiving part that is divided into a detachable bottom-surfacepart, which is disposed below the hand insertion part and is removable,and a fixed bottom-surface part, which is disposed below the handinsertion part and is not removable. The detachable bottom-surface partis supported by the drain water container. However, when the water fromthe hands of the user fails on the surface of the water container thereis a possibility that due to the pressure of the air from thehand-drying water may splash from the surface. Hence there is a need fora system or a device that helps control the effects of spray or splashcreated by high pressure hand dryers. An apparatus that may be retrofitted to a hand dryer to avoid spray on the walls and the floor isdisclosed. The apparatus is easy to operate, install, maintain and iscost effective. The key elements of the product invention are tominimize potential hazards such as slips and falls, to reduce germs andbacteria spreading, to stop the water splashing and collecting under thehand dryer once the user has used the appliance, to eliminate moldappearing on the grout between tiles, to minimize cleaning processes andintervals, to facilitate differently abled or people on wheel chairswith easy cleaning without making their own clothes dirty from thedispersed or splashed water from their hands during hand drying; all ofwhich will benefit companies in reducing expenditure in both labor andcleaning products (costs).

BACKGROUND OF THE INVENTION

Technology improvements have contributed to a rise in the number of handdryer devices and equipment available to companies and other [public]users. Indeed, hand dryers are important as they impact on personalhygiene whilst creating an environment where all can have a mutuallybeneficial hygienic experience.

With a background in design engineering, one often looks for solutionsbeneficial to both professional development and the convenient needs ofothers. The nature of one's profession means the daily use of publicwashrooms. This prompted a recognition and identification ofhealth-safety and hygiene concerns involving the use of publicwashrooms, a problem that is rather commonplace in public washroomfacilities.

I viewed carefully existing hand dryers; firstly, to determine theirmanufacturing utility; and secondly, to ascertain whether or notmodifications are needed, or even a new product invention for a generalpublic hygiene boost for washrooms. I found that there was often moldygrout between tiles under the hand dryers due to water spray, with odorresulting from discoloration of the grout onto the tiles. This situationprevailed regardless of routine hygiene checks by staffers/cleaners.

I observed the way in which most conventional hand dryers were installedand operated. Water tended to leave puddles or slip hazards once theuser has operated it. This became a personal and public concern as wellsince this situation can result in the growth and spread of bacteria. Itcan lead to frequent accidents which can involve companies facingunnecessary law suits for damages caused by injuries to customers andother washroom users.

I have spent considerable time combining personal research with formalinvestigation into patents professionals. I consulted extensively withcorporates and other food companies, to verify if this new productinvention has any merit to environmental policies particularly duringthe global pandemic. Throughout verbal communication with managementteams, they all expressed concerns and possible ways of combatingproblems associated with hand dryers. Positive feedback from businessowners/managers altogether, further reinforced the desire and fulsomeneed, for this new product.

Thereafter, I finally designed the product that was literally achievedthrough a series of professional computer-aided design (CAD). Thisprocess consisted of labor-intensive work, under my guidance as theinventor, with the creation of over a hundred different 3D prototypes.This coupled with intensive 3D printing and over eleven months ofdesigning, prototyping and testing, in an attempt to achieve productperfection. In the process, I acquired rudimentary and other high-techskills in operating a 3D printer to reduce the heavy cost ofprototyping. Eventually. I created my own prototype testing facility toachieve product perfection that is reflective of the modern hand dryerequipment.

The idea here is to demonstrate product efficacy in terms of technologyimprovements. The latter will be most demonstrative by the product'susers finding it easy to operate. Companies and other public washroomproviders will recognize the cost-effectiveness of the product, easyinstallation and less difficulty in product maintenance. In generalterms, this new hand dryer aims to improve hygiene protocols for masscustomer-users whilst enhancing the eco-friendlier image and reputationof companies and other public entities.

SUMMARY OF THE INVENTION

The invention discloses a splash guard for a drying device. The splashguard includes a housing having a first side surface, a second sidesurface, a back surface, a base and a drawer fitting portion in a bottomsurface. In various embodiments the base includes a hole incorporated ina predetermined position to allow a fluid to flow through it. In variousembodiments the drawer includes a drawer front portion, a drawer backportion, a first drawer side portion and a second drawer side portion,removably fitted to the drawer fitting portion and comprising a recessmolded at the bottom surface to facilitate removing the drawer from thedrawer fitting portion. In various embodiments a perforated drip tray isremovably attached over the base, wherein the drip tray is configured toprevent splashing of a fluid displaced from a drying wet surface anddirect the fluid to the hole. The splash guard further includes a hookhaving a first end attached to the back surface and a second end havinga locking attachment fitting into the recess and configured to hold thedrawer in a locked position.

In some embodiments the perforated drip tray has an anti-reflectivesurface. In various embodiments the perforated drip tray includes anaperture that fits along the circumference of the hole in the base. Invarious embodiments the drawer is configured to receive the fluid fromthe hole. In various embodiments the drawer front portion has one ormore fluid level indicators and a notch. In some embodiments the drawerincludes a heater element tray placed inside the drawer. The heaterelement tray is configured to be heated up and dry the fluid when thedryer device turns on. In various embodiments the drawer back portionhas an opening. In various embodiments the hole is configured to fit atubular extension to drain the fluid to a drainage system. In variousembodiments the hook is L shaped. In various embodiments the hook ismade of a polymer.

In various embodiments the back surface includes a geometric shapeselected from circular, square, rectangular, triangular or any othergeometric shape. In various embodiments the back surface includes holesto attach the splash guard to a surface through screws. In variousembodiments the surface includes wall, cupboard or portable stands. Invarious embodiments the housing includes a geometric shape selected fromcircular, square, rectangular, triangular or any other geometric shape.In various embodiments the splash guard is made of silicone, rubber,polyurethane, polycarbonate, aluminum, stainless steel, ceramic, or anysuitable material. In various embodiments the splash guard has ananti-microbial coating.

The Claim advantages being made are in accordance with the benefits tobe derived from this invention. The product will aid in the improvementin hygiene standards with less odor emanating from lavatories and/orwashrooms. Enable reduction in potential hazards; namely slips andfalls, all of which can result in litigation against companies. Theproduct will contribute to improved washroom hygiene, with limitlessbusiness benefits. These benefits are: increased employee productivity,increased engagement and morale. Customer retention, positiveword-of-mouth and increased sale are all likely as well. Incrementally,such benefits can be converted into increased profit margins. Also, thisproduct will have cost-impact benefits on companies and public concernsin terms of reducing labor cost by at least 30%.

Moreover, the hand dryer splash guard according to one embodimentbehaves as a guard for a disabled person using a wheelchair as itprevents the water from their hands to splash over their own clothes andface. People on wheelchair when uses a public washroom and tends toclean their hands using hand dryers, they have to position beneath thehand dryer which ultimately causes water from their hands to splash overtheir body, face and clothes. In an embodiment, the splash guard ofpresent disclosure installs beneath the hand dryer to collect the waterbeing splashed during the drying of hands.

Additionally, the product invention will have key elements ofdurability, affordability and warranty. For instance, anti-microbialcoating will be used to enhance product endurance. By applying this typeof material also, it will help to keep the surface of the productcleaner by inhibiting the growth of bacteria, mold and mildew. Theproduct has been carefully designed to reduce the cleaning cost on laborand cleaning products on a daily basis. Its cost-effectiveness will beevidenced through a company installing this product and seeingproductivity within eighty weeks of installation. The product itself,will have a standard one-year guarantee or warranty.

This and other aspects are described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention has other advantages and features, which will be morereadily apparent from the following detailed description of theinvention and the appended claims, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a splash guard, in isometric view.

FIG. 2A shows the splash guard, in side views, showing the housing.

FIG. 2B shows the splash guard, in front view.

FIG. 2C illustrates the back-side view of the splash guard.

FIG. 3 illustrates the perforated drip tray, in isometric view.

FIG. 4A illustrates the drawer, in isometric view.

FIG. 4B illustrates the drawer handle in the recess.

FIG. 5 illustrates the exploded view of the hand dryer splash guard.

FIG. 6 illustrates the exploded view of the hand dryer splash guard, inthe backward direction.

FIG. 7 illustrates the tubular extension fitted to the hole in the base.

FIG. 8 illustrates the molding of the tubular extension on the bottomside of the housing.

FIG. 9 shows the opening in the drawer that accommodates the tubularextension.

FIG. 10 shows the hook, in an isometric view.

FIG. 11A shows the front view of dryer device and the splash guard.

FIG. 11B shows the side view of the dryer device along with the splashguard.

FIG. 11C shows the side view of the dryer device and the splash guard,with the splash guard placed much below the dryer device.

FIG. 12A illustrates the fitting of the back surface of the splash guardand the v-shaped hand dryer.

FIG. 12B shows the v-shaped hand dryer fitted with the splash guard.

Referring to the drawings, like numbers indicate like parts throughoutthe views.

DETAILED DESCRIPTION OF THE EMBODIMENTS

While the invention has been disclosed with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt to a particular situation or materialto the teachings of the invention without departing from its scope.

Throughout the specification and claims, the following terms take themeanings explicitly associated herein unless the context clearlydictates otherwise. The meaning of “a”, “an”, and “the” include pluralreferences. The meaning of “in” includes “in” and “on.” Referring to thedrawings, like numbers indicate like parts throughout the views.Additionally, a reference to the singular includes a reference to theplural unless otherwise stated or inconsistent with the disclosureherein.

The present subject matter is further described with reference to FIG.1-FIG. 11B. It should be noted that the description and figures merelyillustrate principles of the present subject matter. It is thusunderstood that various arrangements may be devised that, although notexplicitly described or shown herein, encompass the principles of thepresent subject matter. Moreover, all statements herein recitingprinciples, aspects, examples, and embodiments of the present subjectmatter, as well as specific examples thereof, are intended to encompassequivalents thereof.

The invention discloses a splash guard that may be retrofitted to a handdryer device to avoid spraying of water on the floor and on the walls.The splash guard is attached underneath the dryer device and isconfigured to catch the water displaced from a user's drying wet hands.The splash guard is formed of a housing that has side walls, a base, aperforated drip tray and a drawer arrangement to hold the displacedwater. The splash guard is attached to a surface like walls, cupboardsor stands through screws. The housing is hollow and open fronted, forusers to place their hands under the dryer device. The base has a driptray that has perforations. The perforations stop water from splashingand direct the displaced water to drip into a drawer that store up theexiting water. The drip tray may be removed to clean the base and thetray. The walls and the perforated drip tray prevent water from beingsplashed in all directions, including the sides. The housing has adrawer fitting portion in the bottom surface. A drawer may be pushedinto the drawer fitting portion and be removed. The drawer catches waterthrough the hole in the base and stores it for removal at a later time.In various embodiments a hand dryer device is attached over the splashguard. In various embodiments the back surface of the splash guard hasdifferent geometric shapes to accommodate the hand dryer device.

In various embodiments the present subject matter is a splash guard 100that may be attached to a hand dryer device. The splash guard 100 asshown in FIG. 1 includes a housing 110 that has a first side surface112, a second side surface 114, a back surface 116, a base 120 and adrawer fitting portion 126 in a bottom surface 118. The first sidesurface 112, a second side surface 114 acts as walls and prevents waterfrom splashing to the floor or the surface to which the hand dryerdevice is attached to. In various embodiments the base 120 includes ahole 122 that is bored in a predetermined position to allow a fluid toflow through it. The housing also includes a bottom surface thatincludes a drawer fitting portion 126 into which a drawer is fitted andmay be removed when necessary. In various embodiments the housing isinjection molded. In various embodiments the housing 110 is made ofsilicone, rubber, polyurethane, polycarbonate, aluminum, stainlesssteel, ceramic, or any suitable material. FIGS. 2A, 2B and 2C show theside view, front view and back view of the splash guard 100. The splashguard 100 has a geometric shape selected from circular, square,rectangular, triangular or any other geometric shape. The splash guardhas high impact strength and is resistant to chemical corrosion.

In various embodiments the splash guard 100 as shown in FIG. 3 includesa perforated drip tray 150 that is placed over the base 120 and may beremoved. The surface 156 of the drip tray is anti-reflective. Theanti-reflective surface 156 avoids triggering of the sensors attached tothe hand dryer device. The hand dryer device may include infraredsensors or any other sensor that may detect the movement of handsunderneath the blower. The drip tray 150 has perforations 154 thatprevent splashing of a fluid displaced from a drying wet surface. Theperforations break up the wind force from the drier device thus avoidingthe splashing of the fluid. In an exemplary embodiment the drip tray 150has multiple funnel shaped small holes that help break down the highspeed air pressure blowing from the hand dryers and direct the water tothe hole 122. The drip tray 150 also includes an aperture that sits overthe hole 122 in the base 120 of the housing. In various embodiments thedrip tray 150 directs the fluid to the hole 122 through the aperture 152and the fluid exits the base 120 to a drawer 130 that is configured tocollect the fluid. The drip tray 150 may be removed from the base easilyfor cleaning. The perforated drip tray 150 is injection molded and ismade of polymer. The drip tray has high impact strength and is resistantto chemical corrosion.

In various embodiments the splash guard 100 includes a drawer 130 asshown in FIG. 4A. The drawer 130 includes a drawer front portion 132, adrawer back portion 134, a first drawer side portion 136 and a seconddrawer side portion 138. The drawer is fitted to the drawer fittingportion 126 along the first drawer side portion 136 and the seconddrawer side portion 138. In various embodiments the drawer has a recess128 molded at the bottom surface of the drawer. The recess 128facilitates removing the drawer 130 from the drawer fitting portion 126using the fingers of a user as shown in FIG. 4B. In one embodiment therecess 128 is a hidden drawer handle to pull the drawer out afterreleasing the hidden lock or hook 166. The drawer is fitted in thedrawer fitting portion 126 such that the hole 122 in the base opens upin the drawer.

In one embodiment the fluid that falls on the base 120 is collected inthe drawer 130 through the hole 122. In various embodiments the drawerfront portion 132 has one or more fluid level indicators 140 and a notch142. The level of fluid collected in the drawer may be seen from outsidethrough the fluid level indicators 140. The fluid level indicators 140are transparent windows through which the level of water collected maybe seen. In an exemplary embodiment the fluid level indicators 140 areoval shaped transparent water level windows that show the water level inthe drawer. The drawer 130 is removed from time to time to dispose thefluid collected in the drawer. The notch helps in the easy removal ofthe drawer from the drawer fitting portion 126. In some embodiments thedrawer includes a heater element tray 148 as shown in FIG. 5 and FIG. 6.The tray 148 is placed on the inside of the drawer 130. In variousembodiments when the hand dryer comes on, it heats up the tray 148 andhelps the drained water collected in the tray 148 to evaporate. Anexploded view of the drawer arrangement is shown in FIGS. 5 and 6. Thedrawer is injection molded and is made of polymer. The drawer has highimpact strength and is resistant to chemical corrosion.

In one embodiment the hole 122 in the base 120 is configured to fit intoa tubular extension 146 as shown in FIG. 7 and FIG. 8. The tubularextension 146 extents into the drainage system carrying the fluidreceived from the hole 122 to the drainage system. This avoids the needto manually empty the drawer.

In various embodiments in such an arrangement the drawer back portion134 has an opening to accommodate the tubular extension as shown in FIG.9.

In various embodiments the splash guard 100 has a hook 160 to lock andunlock the drawer to the drawer fitting portion 126 as shown in FIG. 10.The hook has a first end 162 attached to the back surface 116 and asecond end 164 having a locking attachment 166 fitting into the recess128. In various embodiments the hook is configured to hold the drawer130 in a locked position preventing the drawer to be opened and closedunwantedly. In one embodiment the locking attachment 166 is configuredto automatically lock in the drawer when the drawer gets pushed in tothe housing. In various embodiments to unlock the drawer, the second end164 having the hook 166 is pressed down allowing the hook to flex andmove out of the recess 128 in the drawer. In various embodiments thehook is injection molded and is made of a polymer. The hook has highflexural strength, low friction and has high impact strength.

In some embodiments the back surface 116 may include geometric shapesconfigured to accommodate a drier device. The geometric shape may becircular, square, rectangular, triangular or any other geometric shape.In some embodiments the splash guard is attached to a surface throughscrews. The back surface 116 comprises holes 170 to hold the screws. Invarious embodiments the surface includes wall, cupboard or portablestands. In various embodiments the splash guard 100 is attachedunderneath a hand dryer 200. The splash guard 100 is attached to thesurface to which the hand dryer is attached. The air from the hand dryerdries the hand while the splash guard 100 is configured to catch thewater displaced from a user's drying wet hands. The attachment of thesplash guard 100 underneath the hand dryer 200 is shown in FIG. 11A-11C.In one embodiment as shown in FIG. 12A the back surface may be molded tofit underneath a v-shaped hand dryer 200. The splash guard 100 has ascooped profile 180 allowing it to slide neatly underneath the dryer asshown in FIG. 12A. This provides a tight seal and ensures that all thewater blown from the hands is collected safely in the splash guard 100.FIG. 12B shows the v-shaped hand dryer fitted with a splash guard. Invarious embodiments the splash guard has an anti-microbial coating. Thecoating enhances the endurance of the splash guard and keeps the splashguard surface clean by inhibiting the growth of bacteria, mold andmildew.

The advantage of the splash guard for a hand dryer device includecollecting and holding the collected water within the product andpreventing water from splashing back up onto the user's hand and sidesof the guard by the unique perforated tray hence preventing mold andmildew damages on the grout between the tiles of the floor under thehand dryer and avoiding potential slip hazards. Also the inventionimproves the hygiene standards, provides cleaner washroom facilities,and avoids smell or odor. Further the product is easy to operate, easyto install, easy to maintain, is cost effective and cleaning cost onlabor and cleaning products is reduced on a daily basis. Further, thesplash guard helps differently abled users of the hand dryers toconveniently use the hand dryer without splashing the water on theirhands over their clothes, body and face.

Although the detailed description contains many specifics, these shouldnot be construed as limiting the scope of the invention but merely asillustrating different examples and aspects of the invention. It shouldbe appreciated that the scope of the invention includes otherembodiments not discussed herein. Various other modifications, changesand variations which will be apparent to those skilled in the art may bemade in the arrangement, operation and details of the system and methodof the present invention disclosed herein without departing from thespirit and scope of the invention as described here.

1. A splash guard (100) for a drying device comprising: a housing (110) comprising a first side surface (112), a second side surface (114), a back surface (116), a base (120) and a drawer fitting portion (126) in a bottom surface (118), wherein the base (120) comprises: a hole (122) incorporated in a predetermined position to allow a fluid to flow through it; a drawer (130) comprising a drawer front portion (132), a drawer back portion (134), a first drawer side portion (136) and a second drawer side portion (138), removably fitted to the drawer fitting portion (126) and comprising a recess (128) molded at the bottom surface (118) to facilitate removing the drawer (130) from the drawer fitting portion (126); a perforated drip tray (150) removably attached over the base (120), wherein the drip tray (150) is configured to prevent splashing of a fluid displaced from a drying wet surface and direct the fluid to the hole (122); and a hook (160) having a first end (162) attached to the back surface (116) and a second end (164) having a locking attachment (166) fitting into the recess (128) and configured to hold the drawer (130) in a locked position.
 2. The splash guard (100) as claimed in claim 1, wherein the perforated drip tray (150) comprises an anti-reflective surface (156).
 3. The splash guard (100) as claimed in claim 1, wherein the perforated drip tray (150) comprises an aperture (152) that fits along the circumference of the hole (122) in the base (120).
 4. The splash guard (100) as claimed in claim 1, wherein the drawer (130) is configured to receive the fluid from the hole (122).
 5. The splash guard (100) as claimed in claim 1, wherein the drawer front portion (132) comprises one or more fluid level indicators (140) and a notch (142).
 6. The splash guard (100) as claimed in claim 1, wherein the drawer comprises a heater element tray (148) placed inside the drawer configured to be heated up and dry the fluid when the dryer device turns on.
 7. The splash guard (100) as claimed in claim 1, wherein the drawer back portion (134) has an opening (144).
 8. The splash guard (100) as claimed in claim 7, wherein the hole (122) is configured to fit a tubular extension (146) to drain the fluid to a drainage system.
 9. The splash guard (100) as claimed in claim 1, wherein the hook (160) is L shaped.
 10. The splash guard (100) as claimed in claim 1, wherein the hook (160) is made of a polymer.
 11. The splash guard (100) as claimed in claim 1, wherein the back surface (116) comprises a geometric shape selected from circular, square, rectangular, triangular or any other geometric shape.
 12. The splash guard (100) as claimed in claim 1, wherein the back surface (116) comprises holes (170) to attach the splash guard to a surface through screws.
 13. The splash guard (100) as claimed in claim 1, wherein the surface comprises wall, cupboard or portable stands.
 14. The splash guard (100) as claimed in claim 1, wherein the housing (110) comprises a geometric shape selected from circular, square, rectangular, triangular or any other geometric shape.
 15. The splash guard (100) as claimed in claim 1, wherein the splash guard is made of silicone, rubber, polyurethane, polycarbonate, aluminum, stainless steel, ceramic, or any suitable material.
 16. The splash guard (100) as claimed in claim 1, wherein the splash guard comprises an anti-microbial coating. 